Monsodium glutamate also known as MSG, Ve-tsin or E621 is a frequently used ingredient to add umami taste in foods. Monosodium glutamate is the sodium salt of the amino acid glutamic acid. Originally it comes from the Far East, but nowadays it is used in many products. Monosodium glutamate is a controversial additive. Many people claim health problems after eating MSG, on the other hand clinical studies give no reason for concern.
The tongue is sensitive to five tastes—salt, sweet, bitter, sour, and “umami” in the Japanese language, the taste of glutamate. There is no analogous word to describe this taste quality in the English language. “Umami” is used by the Japanese to describe the taste of MSG as well as the meaty taste of certain fish and broth. It should be noted that although glutamate is often referred to as flavour enhancer, this probably incorrect as the umami taste is a taste on it's own. Therefore, the term flavour or taste enhancer will not be used to avoid confusion. Instead, the taste of glutamate will be described as umami taste.
Healthy eating is essential for maintaining a good quality of life, especially in an ageing population. MSG can improve food palatability and acceptance, increase salivary flow and immunity, and reduce oral complaints in both sick and healthy elderly.
Consumers continue to have questions regarding MSG's safety and efficacy. However, there is general agreement in the scientific community, based on numerous biochemical, toxicological and medical studies over the last twenty years, that MSG is safe for the general population, including pregnant and lactating women, and children. The “Chinese Restaurants syndrome” takes its name because it generally occurs after ingestion of Chinese foods. As responsible of this illness glutamate has always been indicated, because of its frequent use in Chinese cuisine and it was suggested that there might be idiosyncratic intolerance in some individuals. Symptoms include broncho-constriction in asthmatics. However, controlled double-blind crossover studies have failed to establish a relationship between Chinese Restaurant Syndrome and ingestion of MSG, even in individuals reportedly sensitive to Chinese meals and asthmatics.
After many years of scientific evaluations and meetings the Joint FAO/WHO Expert Committee on Food Additives (JECFA) decided in 1987 that monosodium glutamate was allocated with an “Advised Daily Intake (ADI) not specified”. This indicates that no toxicological concerns arise associated with its use as a food. In 1991 the European Community's Scientific Committee for Food (SCF) confirmed the safety of MSG. A subsequent review by the Federation of American Societies for Experimental Biology (FASEB) and the federal Drug Administration (FDA) came to the same safety conclusions as the JEFCA.
Nevertheless, and despite the fact MSG is often required to be included among the list of food ingredients, many food manufacturers have increasingly adopted a strategy of placing additional prominent messages regarding MSG on food labels. As a result, food labels advertising “No added MSG” have become commonplace. One possible consequence of such labels is that they generate and reinforce beliefs that MSG is harmful and/or an unsafe ingredient. Recent research on the effects of different types of label information suggests the possibility that these messages may also influence the acceptability of products containing added MSG. A recent study examined the impact of information specifying the addition of MSG to foods or not. The attitudes towards MSG were evaluated and found to be generally negative.
Hence, whereas MSG or glutamate can actually aid to providing healthier eating habits, consumer acceptance is generally low, even despite the proved safety of MSG. There is thus a need for MSG based umami active compositions that constitute natural food ingredients and that can be mentioned on food product labels as such or do not have to be mentioned on the labels at all.
One such composition has been described in EP 1 082 027, which relates to a clear tomato concentrate comprising hydrolysed proteins, amongst other glutamate. The clear tomato concentrate of EP 1 082 027 is produced by processing tomatoes so as to obtain two fractions, the serum and the pulp, where after the serum is further concentrated to a value of e.g. 80 Brix and then hydrolyzed or vice versa. Both acid and enzymatic hydrolysis are suggested in EP 1 082 027. The obtained clear tomato concentrate may subsequently be dried on a variety of materials. Production of tomato serum as such has been described in a variety of prior art documents, such as WO 03/101223 and WO 95/16363.
The clear tomato concentrate obtainable by the method disclosed in EP 1 082 027 has several draw-backs. First of all, in spite of the fact that the tomato concentrate is described as clear, i.e. transparent or having low opacity, it is in fact red to dark red. It is noted that the serum in accordance with EP 1 082 027 has a lycopene level of about 5 ppm at a Brix value of 5, as described by WO 95/16363 to which EP 1 082 027 refers, such that after concentration to a Brix value of 60 or higher, the lycopene level must be 60 ppm or higher, thus giving a far more intense red colour than do fresh tomatoes, having a lycopene level of approximately 25, according to USDA. This problem becomes particularly evident when applying said concentrate at levels exceeding approximately 0.5%, thus greatly reducing the applicability thereof in a whole range of products wherein redness is undesirable, e.g. in white soups such as cream soups, bouillons, such a chicken bouillons and beverages. Secondly, it was found that following the teachings of EP 1 082 027, concentrates are obtained that still possess tomato taste/flavour as well as tomato smell and giving a specific sour taste. Thus, these products are in fact unsuitable for application in substantial amounts, i.e. in amounts exceeding approximately 0.5 wt %, in non-tomato based products. Thirdly, EP 1 082 027 mentions that it solves the problem of Chinese Restaurant Syndrome, which as described above is a non-existing syndrome.
To minimise the amount of MSG in food products it would be desirable to provide an umami active fraction for the use of enhancing the umami taste, preferably by at least two fold or even at least 3 fold. Therefore, one object of the invention is to provide for an umami active fraction for the use of enhancing the umami taste.
In addition, as explained above, there still exists a need to for a umami active tomato fraction comprising glutamate which can be used as a natural umami active fraction for adding a umami taste to a wide variety of food products, without adding an undesired off taste. Moreover, it would be desirable to provide for a more cost effective and robust process to produce such umami active tomato fraction.